Summer-Fall Leaf Sample
Treatment ThresholdTo determine if the population of citricola scale has reached the treatment threshold, collect one leaf from the NE corner of each of 25 trees in 4 evenly spaced rows in the orchard (a total of 100 leaves per orchard). For each row, count the number of leaves out of 25 that have at least one live nymph and enter that number in the table below.
No. of leaves
If any row has a box checked 'treat this year' then treat the whole orchard.
If any row has a box checked 'consider treating', then it is a judgment call.
For more information on sampling and evaluating scales see Citricola Scale Citrograph Article 1999.